General Purpose GP Cement 20kg

General Purpose (GP) cement is the standard binding agent used across Australian building work, and this 20kg bag conforms to Australian Standard AS3972 Type GP requirements. It is the cement to reach for when you are mixing concrete, mortar, render or grout on a roofing or building job, and it is supplied locally for consistent quality batch to batch.

Key Features

• Meets AS3972 requirements for general purpose cement
• 20kg bag, easy to handle on site
• Suits concrete, mortar, render and grout mixes
• Consistent strength development for reliable results
• Works with common supplementary cementitious materials
• Supplied in a weather-protected multi-wall paper sack

Key Properties And Compliance

Typical performance figures per Cement Australia data for AS3972 Type GP cement: an initial setting time of 60 to 150 minutes (minimum 45 minutes), a final setting time of no more than 6 hours, and a soundness of under 3mm (maximum 5mm). Compressive strength develops to roughly 30 to 42 MPa at 3 days, 43 to 54 MPa at 7 days, and 54 to 65 MPa at 28 days.

Mix Guidance

• Concrete general use: 1 part cement, 2.5 sand, 4 aggregate
• Concrete paths and driveways: 1 part cement, 2 sand, 3 aggregate
• Concrete foundations: 1 part cement, 3 sand, 3 aggregate
• General purpose mortar: 1 part cement, 4 sand
• Render: 1 part cement, 3 sand

Applications

• Bedding and pointing mortar on tiled roofs
• Concrete for footings, slabs, paths and driveways
• Render, grout and general repair mixes
• Structural, civil and domestic building work

Storage And Handling

Store the bag off the ground in dry conditions. Moisture causes premature hydration and reduces the usable life of the cement, and bagged cement older than 6 to 12 months may lose performance. Use clean water, measure the mix accurately, and cure the concrete or mortar for at least seven days for full strength. GP cement is highly alkaline, so wear a mask against dust and protect skin and eyes when handling.

What You Need To Complete The Job

For roof pointing and bedding, pair the cement with brickie sand and add oxide colour to match the mortar. Mix it with an OX PRO 1600W mixing drill and apply with a gauging trowel. Browse the Concreting range for more.

Frequently Asked Questions

What is GP cement used for?

GP (general purpose) cement is the all-round binder for concrete, mortar, render and grout. On a roof it is the cement used in bedding and pointing mixes under ridge and hip tiles, and in general building it handles footings, slabs, paths and repairs.

Is this cement compliant with Australian standards?

Yes. The cement conforms to Australian Standard AS3972 Type GP requirements for general purpose and blended cements, so it is suitable for structural and general building use.

How much concrete does a 20kg bag make?

A 20kg bag of cement is one part of a mix, not a finished product. Following the mix ratios, it combines with sand and aggregate to produce a batch of concrete or mortar. Use the ratios above and scale to the job.

How should I store the cement?

Keep the bag off the ground and dry. Moisture starts the hydration process and weakens the cement, and older bags lose performance, so use the bag within a reasonable time of purchase.

Can I order for delivery or pickup?

Yes. You can order online and choose Australia-wide delivery or pickup from our Truganina trade counter in Melbourne’s west. Delivery windows depend on your postcode, and we send a confirmation once your order is ready. For any questions call (03) 93941400 or email orders@singhroofingsupplies.com.au.